India To Attempt Soft-Landing Near The Moon’s South Pole

The Chandrayaan-2 mission’s rover rolls across the moon’s south polar region on its six wheels in this artist view. ISRO

India is poised to launch its second mission to the moon, this one far more adventurous than the first. The Chandrayaan-2 mission was slated to lift off this afternoon Central Time (July 14) but was unfortunately postponed for technical reasons. A new launch date will be set soon.

The Pragyaan rover de-ramps from the lander, ready to explore. ISRO

This second lunar voyage includes a lunar orbiter, lander and rover. The orbiter will hover 62 miles (100 km) above the lunar surface and look for a suitable landing spot in the never-before-visited south polar region. It will also map lunar topography, look for water ice beneath the surface using ground-penetrating radar and study the moon’s composition.

Later, the lander, named Vikram after Vikram Sarabhi (father of the Indian space program), will separate and drop into a lower orbit before beginning its powered descent to the surface in early September. Mission success would make India the fourth country — after the United States, Russia and China — to land on the moon. Once there, the lander will study the moon’s scant atmosphere called the exosphere, measure moonquakes and take pictures.

India’s Vikram lander will power down to the moon’s south polar region, a rugged area with significant water ice. Virtual Moon Atlas

Tucked inside the lander is a 60-pound (27 kg) rover nicknamed Pragyaan, a word meaning “wisdom” in Sanskrit. Pragyaan will roll down a folding ramp and tool around the surface taking pictures and performing on-site chemical analysis of moon dirt. The landing site is located between the craters Manzinus C and Simpelius N near 70° south latitude. Although the orbiter will operate for a year, the lander and rover are designed to function for just one lunar day, a period of time equal to about 14 Earth days. That’s how long the sun is up over any one spot on the moon. Night, when temperatures plummet to –280° F (–173° C), is far more demanding on equipment.

Shadowed craters near the lunar poles preserve water as ice as well as bound into other minerals. The moon’s axis is tilted just 1.5° so it has no seasons and parts of polar craters’ floors never see sunshine. ISRO

Indian scientists are interested in the south pole because a significant amount of water ice has been detected there from orbit. Enough to make a good source of water for future astronauts and who knows, maybe even that first lunar colony. Dare to dream, right? Water on the moon sounds like a contradiction, but there are two potential sources. The first is comets, many of which have collided with the moon over its lifetime. Water molecules released during the impacts could have migrated to the poles where they condensed as ice in the walls and floors of permanently-shadowed craters there.

A closer view of the proposed landing site between Manzinus C and Simpelius N. ISRO

The moon isn’t tilted as much as the Earth, so the floors of some deep craters at the poles never see sunshine and consequently experience temperatures no warmer than 238° F below zero (–150° C). That’s what I call a deep freeze. A second source of water might originate when hydrogen atoms from the sun called protons slam into oxygen-containing rocks; hydrogen and oxygen combined (and may still be combining) in a chemical reaction to make good old H2O.

The mission will also test equipment and methods for future missions as well as demonstrate India’s technical prowess. Chandrayaan-2 follows on the heels of the 2008 Chandrayaan-1 lunar orbital mission which successfully detected traces of water in many areas of the lunar crust. We wish India well and hope it launches to the moon very soon!

More on the mission including updates are at Chandrayaan-2 ISRO.